During the manufacture of a vehicle, a number of steps (e.g., tests) may be performed to ensure, or help to ensure, that various vehicle subsystems are functioning properly. The subsystems involved, and the associated test procedures may vary considerably, as may the consequences of a malfunction.
While it is certainly desirable to any vehicle manufacturer that all the subsystems of a vehicle it produces operate properly when the vehicle leaves the factory, it should be understood that a heightened level of scrutiny is typically given to critical vehicle functions such as steering and braking. With respect to a brake system, for example, it may be desirable to check for leaks, for proper pedal pressure, for proper pedal travel, etc. In this manner, it can be reasonably ensured that the vehicle will function safely and properly after delivery to a customer.
To this end, a variety of devices and methods have been developed and employed to test vehicle brake systems and/or vehicle brake system components at some stage during the vehicle manufacturing process. A first category of such devices includes simple shaft-based devices that may be placed between a vehicle brake pedal and another vehicle structure to maintain the brake pedal in a depressed state while a user inspects the brake system from outside the vehicle. A second and more complex category of brake system testing devices are also known. These devices are normally designed to rest on the floor or the driver's seat of a given vehicle and typically include a reciprocating actuator that is provided to repeatedly depress and release a brake pedal. Operation of these more complex devices may be conducted remotely, such as by a remote control held by a user while outside of the vehicle of interest.
Yet other devices have been developed that do not interact with a brake pedal but, rather, interact directly with the brake booster of a vehicle's brake system to create brake pressure independently of the actuation of the brake pedal. Creation of brake pressure in this manner gives rise to travel of the brake pedal. The amount of travel of the brake pedal may then be detected using a sensor, etc.
While each of the devices and their methods of use may function to produce the intended result, there are drawbacks to each. For example, the devices of the first simplistic category mentioned above are essentially just braces for holding a brake pedal in a fixed depressed position while a user observes other parts of a vehicle's brake system.
The more complex devices of the aforementioned second category of brake system testing devices may provide additional functionality, such as brake pedal stroking by means of an included actuator. However, these devices are also generally expensive to produce, cumbersome to handle, and require sufficient space on either the floor or seat of the vehicle of interest. This latter characteristic also typically means that a user of the device cannot occupy the driver's seat of the vehicle while the device is in use.
It should be apparent that use of brake system testing devices such as those that connect to a brake booster or similar brake system component also requires a fairly complex setup, and further necessitates a connection to pressurized, closed-loop components. Clearly, this is a more time consuming and complicated process than one that acts directly on the brake pedal itself, and this process also still requires some means of directly measuring brake pedal travel.
With respect to testing vehicle brake systems during the manufacturing process, it should also be realized that it is today fairly commonplace for a given manufacturing facility to produce more than one vehicle model. Therefore, it is preferable that a brake system testing device be usable with more than one vehicle. Otherwise, it may be necessary to employ a dedicated testing device for each vehicle produced, which increases costs, requires additional storage space, complicates the process, and increases the likelihood for a testing error.
In this regard, while the above-mentioned brake system testing devices of the second category may be the most useful due to their ability to both depress a brake pedal with a given force and also measure brake pedal travel, such devices normally suffer from an inability to easily operate with multiple vehicle models. This deficiency may be due to space limitations, to differences in distances, angles, etc., between the brake pedals of different vehicles and a supporting area for the devices, and/or for other reasons.
Consequently, it can be understood from the foregoing observations that there is a need for a vehicle brake system testing device that can be cost-effectively produced, is easy to manipulate and operate, and may be used to test the brake systems of multiple vehicles. Brake system testing devices and methods of the invention satisfy this need.